The DevTest Portal uses the Grails framework. In DevTest 10.3, the logging for the portal is split into portal.log and portal-grails.log

Additional Information:

Here are the differences of Portal related logs from DevTest 10.3:

portal.log・・・Information about the booting up and closing down of the Portal and reshubportal-grails.log・・・Logging information about the phoenix portal webappportal-reshub-grails.log・・・Logging information about the reshub component